I only have experience with my brothers SP3 and a SP4 I got for work, but both had constant issues, particularly with DPI scaling of applications.
That's not to mention the god awful battery life, the constant thermal throttling (that's what happens when you don't have a fan), the weird issues with the thing not going into sleep mode consistently, and plenty of other seemingly random Windows 10 quirks I don't get on my desktop machines.
There wasn't a day that went by where I didn't have to face some kind of frustration when I had one for work. I swapped it for a laptop after a couple of months.
Primarily it was the DPI scaling issues that did it for me, personally. I just don't think Windows is ready to be used at anything but 100% scaling, and that's just impossible with 4K resolution screens that are 13" or smaller unless you have eagle eyes.